function [bonds,components] = rbg2abg(name,rbonds,rstrokes,rcomponents,port_coord,port_name,\
				      infofile,errorfile)

% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %% Version control history
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %% $Id$
% %% $Log$
% %% Revision 1.34  1998/07/02 19:41:29  peterg
% %% Fixed empty port string bug - set to null string.
% %%
% %% Revision 1.33  1998/07/02 17:16:06  peterg
% %% Commented out redundent code -- obsolete due to new default mechanism
% %%
% %% Revision 1.32  1998/07/02 15:12:05  peterg
% %% Added hard error reporting
% %% Added error when two unlabled bonds point in.
% %%

% %% Fixed  no causal strokes bug.
% %%
% %% Revision 1.1  1996/08/04 18:30:14  peter
% %% Initial revision
% %%
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%







%Default to no components
components = [0];

% Xfig scaling factor
scale = 1200.0/2.54546;

  eval(['[comp_type, comp_name] = ', name, '_cmp(i)']);

  % There are n_comp_bonds bonds on this component with corresponding index
  [index,n_comp_bonds] = getindex(comp_near_bond,i);

  if index(1,1)==0
    mtt_error(sprintf("Component %s (%s) has no bonds", comp_name,
    comp_type),errorfile);
  end;
  
  % Create the signed list of bonds on this component
  one = ones(n_comp_bonds,1);
  bond_list = index(:,1); %  bond at component
  
  % Check that all bonds are unique -- error if not
  if unique(bond_list)==0
    mtt_error(sprintf("Component %s (%s) is at both ends of a bond", comp_name,
    comp_type),errorfile);
  end;
    

  % which end of bond at component?
  bond_end = index(:,2); 
  direction = -sign(bond_end-1.5*one);
  signed_bond_list = bond_list.*direction;

	    out_bonds++;
	    port_name_i = "out";
	  end;
	elseif (unlabelled_ports==2)
	  if port_direction>0
	    if (++in_bonds>1)
	      mtt_error(["More than one unlabelled INport on component " \
			comp_name " (" comp_type ")"],errorfile);
	    else
	      port_name_i = "in";
	    end
	  else
	    if (++out_bonds>1)
	      mtt_error(["More than one unlabelled OUTport on component " \
			comp_name " (" comp_type ")"],errorfile);
	    else
	      port_name_i = "out";
	    end
	  end;
	else
	  mtt_error(["More than two unlabelled ports on component " \
		    comp_name " (" comp_type ")"],errorfile);
        end
	mtt_info(["Defaulting port name [" port_name_i "]\t on component " \
		  comp_name " (" comp_type ")" ],infofile);
	port_name = [port_name; ["[" port_name_i "]"]];	# add to list
	[port_name_index,junk] = size(port_name); # the corresponding
				# index
	port_bond(port_name_index,:) = signed_bond; # add to port bond
      else  
      	port_name_i = deblank(port_name(port_name_index,:));
	port_name_i = port_name_i(2:length(port_name_i)-1) # strip []
      end;
      
      % Replace by alias -- if any
    	eval( ["alias = ", comp_type, '_alias';]); # Get aliases
    	if is_struct(alias)		# are there any aliases
          if struct_contains(alias,port_name_i) # Is this an alias?
	    eval(["new_port_name_i = alias.",port_name_i]);
	    mtt_info(["Expanding  port name [" port_name_i "]\t on component " \
		      comp_name " (" comp_type ")\t to [" new_port_name_i "]"],infofile);
	    port_name = replace_name(port_name, \
				     ["[",new_port_name_i,"]"], \
				     port_name_index);
	  end
      	end
      end
    end

    % bond
    signed_bond_index = port_bond(i);
    [other_bond_index,n_other] = getindex(port_bond,-signed_bond_index);
    if n_other == 1
      other_port_name = port_name(other_bond_index,:);
      [other_subport,n_other_subports] = split_port(other_port_name, ',');
      if n_other_subports~=n_subports
	mtt_error(['Vector ports ', port_name_i, ' and ', other_port_name, 'are not compatible'],errorfile);
      end
    else 
      mtt_error(['Vector port ', port_name_i, ' has no matching port'], errorfile);
    end;
    
    if other_bond_index>i %then its not been done yet
      mtt_info(['Vector port: ', port_name_i],infofile);
      mtt_info(['matching: ', other_port_name],infofile);
      % Remove sign info.
      bond_index = abs(signed_bond_index);
      sig = sign(signed_bond_index);
      
      % Put the first element of each port list in the expanded list
      exp_port_name = [exp_port_name; subport(1,:)];
      exp_port_name = [exp_port_name; other_subport(1,:)];

  % Check that number of bonds on the component is the same as the number of
  % ports
  [n_comp_ports,m_comp_ports] = size(port_list);
  if (n_comp_ports~=n_comp_bonds) & ...
	~(strcmp(comp_type,'zero')|strcmp(comp_type,'one'))
    message=sprintf('Component %s (%s) has %1.0f impinging bonds but has %1.0f ports', ...
	comp_name,comp_type,n_comp_bonds,n_comp_ports);
    mtt_error(message, errorfile);
  end;
  
  unsorted_port_list="";
  if n_ports>0 % then there are some named ports
    % so find those associated with the bonds on this component.
    k=0; 
    for j = 1:n_comp_bonds

  else 
    k=0;
  end;
    
#  %Either all ports or no ports should be labelled - write error
#  %message if this is not so
#  if (k~=0)&(k~=n_comp_bonds)
#    mtt_info(['Component ', comp_name, ' (', comp_type, ') has wrong number of labels'], infofile); 
#    mtt_info(sprintf("\tit has %1.0f labels but should have 0 or \
#    %1.0f",k,n_comp_bonds), infofile);
#    portnames=""; 
#    for kk=1:k 
#      portnames=sprintf("%s %s",portnames, unsorted_port_list(kk,:));
#    end;
#    mtt_error(portnames,errorfile);
#  end;
  
  %Compute the number of labeled ports
  [n_unsorted_ports,m_unsorted_ports] = size(unsorted_port_list);
  if m_unsorted_ports==0
    n_unsorted_ports = 0;
  end;
#  n_unsorted_ports,n_comp_bonds
#  % One port defaults:
#  if (n_comp_bonds==1)&(n_unsorted_ports==0)
#    %if (direction(1)<0) & ~strcmp(comp_type,'SS') % Wrong way for default
#    % mtt_error(['One-port ', comp_name, ' (', comp_type, ') has the sign pointing the wrong way '], errorfile);
#    %end;
#    unsorted_port_list = port_list;
#  end;
  
#  %Two port defaults
#  if (n_comp_bonds==2)&(n_unsorted_ports==0)
#    if direction(1)==direction(2) % Wrong way for default
#      % mtt_error(['Two-port ', comp_name, ' (', comp_type, ') does not have through-pointing arrows'], errorfile);
#    end;
#    if direction(1)==1 %in
#      % mtt_info([comp_name, ' in'],infofile);
#      unsorted_port_list = ['[in]';'[out]'];
#    else %reverse the order
#      % mtt_info([comp_name, ' out'],infofile);
#      unsorted_port_list = ['[out]';'[in]'];
#    end;
#  end;
  
#  % Recompute the number of unsorted ports
#  [n_unsorted_ports,m_unsorted_ports] = size(unsorted_port_list);
#  if m_unsorted_ports==0
#    n_unsorted_ports = 0;
#  end;
  
  % Junctions or no lables(order of ports unimportant)
  if strcmp(comp_type,'zero')|strcmp(comp_type,'one')
    for j = 1:n_comp_bonds
      components(i,j) = signed_bond_list(j);
    end
  else %Order of ports is important
    unsorted_port_list, port_list
    if n_unsorted_ports==0
      mtt_error(['Component ', comp_name, ' (', comp_type, ') has no labeled ports'], errorfile); 
    end;
    %Write out the signed bond list in the correct order
unsorted_port_list
for j = 1:n_comp_bonds
      j
      name_k = unsorted_port_list(j,:)
      k = name_in_list(name_k, port_list);
      % Check that it only appears once in port list
      if length(k)>1
	mtt_error(['Component ', comp_name, ' (', comp_type, ') has ports with the same name:  ', name_k], errorfile); 
      end;
      
      %Check that it only appears one in the label list
      kk = name_in_list(name_k,unsorted_port_list);
      if length(kk)>1
	mtt_error(['Component ', comp_name, ' (', comp_type, ') has multiple port labels:  ', name_k], errorfile); 
      end;
      
      if k==0
	mtt_error(['Component ', comp_name, ' (', comp_type, ') has an unrecognised port: ', name_k], errorfile); 
      else
	components(i,k) = signed_bond_list(j);     
      end;
    end;
  end;
end;